The SCHUMANN project aimed to reinforce the foundations of a future modular space ecosystem by developing two major technological tracks: (1) the Refuel Tank (RTa) Functional Satellite Module (FSM), a TRL 5 demonstrator for in-orbit refuelling operations, and (2) the Design and Development Specification for the Satellite Construction Kit (DSSCK), including the supporting DVVP and RESONANCE software tools. Over the course of the project, both objectives were pursued in parallel with frequent coordination to ensure consistency and complementarity.
1. Development and Testing of the Refuel Tank (RTa)
The RTa development started with the consolidation of system-level requirements. The consortium reviewed prior space missions and OSAM concepts to define the functions, constraints, and interfaces required of a functional satellite module focused on refuelling applications. From this baseline, a system architecture was defined that includes mechanical, electrical, and fluidic subsystems. The design phase covered both the Engineering (EM) and Engineering Qualification (EQM) models. The RTa structure was developed based on COTS CubeSat-standard mechanical configurations and integrated high-pressure fluidic lines, valves, sensors, and a modular avionics stack. The team placed particular emphasis on the integration of the HOTDOCK robotic interface, which supports both mechanical connection and fluid/electrical transfer (data + power). In parallel, GMV adapted and implemented the ESROCOS software stack for the RTa, focusing on back-end services, the components control and the graphical user interface. Key performance indicators were achieved on the EM and EQM iterations: fluid transfer at 200 bars under ambient and TVAC conditions. The RTa development significantly matured the technology readiness of the integrated system from TRL 3–4 to TRL 5. The design, integration, and test experience also generated a rich set of lessons learned for future mission preparation. The RTa is seen as a promising candidate for future in-orbit demonstration and commercial applications.
2. Advancements in DSSCK, DVVP and the RESONANCE Tool
In parallel to RTa, SCHUMANN developed a framework to support the design and certification of modular satellite components: the Design and Development Specification for the Satellite Construction Kit (DSSCK).
The first step involved elaborating an ontology-based framework to model FSM concepts and their interrelations, including mechanical, electrical, software, and operational elements. The team consolidated then a baseline of technical requirements covering the application of the DSSCK. A structured DVVP (Design, Verification and Validation Plan) was then defined, offering a practical guideline for FSM developers to ensure compliance with DSSCK standards. It included processes for self-assessment and traceable verification, promoting compatibility and reusability across the ecosystem.
The consortium developed RESONANCE, a software tool implementing the DVVP approach. The RESONANCE tool provides a GUI-based environment where FSM developers can, model new components and integrated FSM, validate their design through pre-defined compliance checks and generate reports and guidance for auto-certification processes. A testing campaign with three third-party companies was conducted. Their feedback confirmed the tool’s usability and potential, and will guide the development roadmap.
